1. Technical Field
The present disclosure relates to a process for manufacturing an integrated membrane of nozzles in MEMS technology for a spray device, and to the spray device that uses such membrane, in particular a spray or aerosol device of an inhaler used for administration of pharmaceutical products, parapharmaceutical products, or perfumes.
2. Description of the Related Art
For example, in applications in the medical field, inhalers of a known type are generally used for administering medicaments in controlled doses or for a wide range of aerosol-based therapies.
An inhaler supplies the medicament, which is in liquid form, as a nebulized dispersion of drops. Preferably, an inhaler is of contained dimensions and generally operated with a battery so that the patient is able to carry it with him and use it in a discrete way.
Inhalers of a known type, for example, of the type described in U.S. Pat. No. 6,196,219, generally comprise a membrane provided with nozzles (or pores) and set facing a reservoir containing the liquid to be nebulized. An actuation element, for example, a piezoelectric actuation element, can be used for deforming the reservoir and causing exit of the liquid through the nozzles of the membrane.
As is known, the effectiveness of a medical treatment depends upon the activity of the active principle, and said effectiveness depends in turn upon the amount of each dose of medicament nebulized and upon the point of impact of the spray. Consequently, the amount of nebulized liquid and the directionality of each spray should be as constant as possible for different sprays, so as to maximize the effectiveness of the medical therapy.
It is clear that the type of membrane of nozzles and the size and shape of the nozzles, as well as the uniformity of the size and shape of the nozzles, are parameters that are particularly important to define the size and directionality of the drops generated and their reproducibility.
Various membranes of nozzles for inhalers have been proposed; however, some of these require a particularly complex manufacturing process, whilst others do not enable a high reproducibility of the nozzles.